1. Field of the Invention
This invention relates, generally, to manufacturing and application of fiber-reinforced concrete and asphalt. More specifically, it relates to an apparatus and methodology for dispensing pre-cut fibers to “on-demand” mixing processes in asphalt and concrete industries, where the addition of such fibers is required at the job site.
2. Brief Description of the Prior Art
Adding various types of Fibers to the mixes of mobile equipment such as asphalt slurry seal, asphalt micro surfacing, and volumetric concrete trucks, among other mobile equipment that require the fibers be added at the job site, has been a long standing practice in these industries. These “on-demand” processes require that the fiber be added at the job site into specific mixing processes. Even though adding fiber to theses mixing processes improves the overall quality and performance of the final product, the difficulty and cost of adding the fiber to these on-demand processes by the contractor often outweighed the benefits of adding the fiber.
Historically, fibers have been added by hand, by the use of on-demand fiber choppers that chop continuous strands into pre-determined lengths, or volumetric dispensers that use pre-chopped fibers. When pre-cut fibers are added by hand, it is nearly impossible to achieve even distribution and quantity of fiber into the mixing process. On-demand choppers provide an adequate method of adding fiber, but require a significant amount of maintenance and constant monitoring to ensure that the fiber is being added properly. Various volumetric dispensers have been tried with very little success. Other dispensers do not provide an even distribution of the pre-cut fibers as the fibers has a tendency to clump and bridge during the dispensing process which negatively affects the quality of the final product.
Certain mechanistic fiber dispensers do exist in the prior art. Examples include U.S. Pat. No. 7,736,569 to Baur et al; U.S. Pat. No. 5,947,645 to Ives et al; U.S. Patent Pub. No. 2004/025542 to Clausen; U.S. Pat. No. 5,931,610 to Ives et al.; PCT Pub. No. WO2009014952 to Ramnarine; U.S. Pat. No. 6,550,362 to Galinat et al; U.S. Pat. No. 3,885,774 to Clipston et al.; and U.S. Pat. No. 4,023,706 to Dearlove et al. However, each of the foregoing references are very complex and have many moving parts, thus overcomplicating the manufacture, use and maintenance of the apparatus. Additionally, the foregoing references can be inaccurate and importantly fail to provide an even distribution of fiber in the concrete.
U.S. Pat. No. 8,162,243 to Wenthe et al. (“Wenthe”) discusses an apparatus for breaking up fiber and transporting the fiber. Wenthe utilizes a rectangular intake chute into which larger fiber masses are placed or dropped. Within the intake chute are vertically-oriented fan-type structures that rotate such that the blades contact the fiber masses and split or separate pieces of fiber from the mass. The fan-type structures each rotate in the same counterclockwise direction. The separated pieces of fiber are a bit larger, and as such, sprockets are positioned underneath the fan-type structures. Adjacent sprockets rotate in opposite directions. The larger pieces of fiber are contacted by the sprockets, thereby further breaking up the larger pieces of fiber into smaller pieces of fiber. The smaller pieces of fiber subsequently drop onto a conveyor belt that transports the smaller pieces of fiber horizontally to a collection bin or other apparatus as desired by the user. There are several drawbacks to the Wenthe apparatus, though, for example the inability to mobilize the apparatus, the potential for fibers to become clogged in the system, and inefficiencies in fiber distribution, among others.
Accordingly, what is needed is a mobile fiber dispenser for pre-cut fibers that is easier to use, more accurate, requires less maintenance, and is more cost effective. However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the field of this invention how the shortcomings of the prior art could be overcome.
All referenced publications are incorporated herein by reference in their entirety. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein, is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
While certain aspects of conventional technologies have been discussed to facilitate disclosure of the invention, Applicants in no way disclaim these technical aspects, and it is contemplated that the claimed invention may encompass one or more of the conventional technical aspects discussed herein.
The present invention may address one or more of the problems and deficiencies of the prior art discussed above. However, it is contemplated that the invention may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the claimed invention should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.
In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which this specification is concerned.